This competitive renewal application seeks support for the continuation of a highly successful Physician-Scientist Program in Aging at Harvard Medical School's Division on Aging and its affiliated institutions. This joint effort involving investigators in basic and clinical departments has excelled in identifying and training outstanding clinicians for research careers in areas central to the mission of the National Institute on Aging. In the previous funding period, we have successfully selected twelve superb young physician-scientists who are well-directed toward gerontologic research careers. The major goal in the next funding period will be to provide exciting opportunities for additional outstanding physicians to engage in intensive training experiences involving didactic and laboratory experiences in the basic and clinical sciences. Enlarged scope and improved quality of the training program will ensure that the Physician-Scientist trainees will be introduced to the current biological concepts and technical aspects of basic science investigation (Phase I) and will apply such expertise toward the elucidation of mechanisms of aging and clinically relevant problems in the elderly (Phase II). A new feature of the present application is the introduction of a greatly expanded program of enrichment activities for the trainees that are identified not only with this program but with other NIA-related research programs. New enrichment activities include a series of educational seminars in Cell and Molecular Biology of Aging, establishment of a society of Gerontology Research Fellows, and annual Research in Aging retreats. The ultimate goal of the program is the development of Physician-Scientists who can advance knowledge and enhance the development of academic, research-intensive programs in the long-neglected areas of biomedical Gerontology and Geriatrics.